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Volvo Planning Driveline Architectures All To Be Plug-in Hybrid Capable; Considering a Range-Extended Electric-Drive Architecture in the Future

19630_1_5The V70 plug-in hybrid demonstrator highlights Volvo’s current PHEV architecture: front-wheel drive combustion engine, electric motor on the rear axle. Click to enlarge.

Volvo is planning all its future driveline architectures with the ability to accommodate a rear-axle electric motor and battery for enabling a plug-in hybrid option, according to Paul Gustavsson, Volvo’s Vice President Business Development and Electrification Strategy.

Volvo’s current plug-in architecture of choice is shown on its V70 diesel PHEV prototypes: combining a front-wheel drive engine (diesel initially) with an axle-integrated rear-wheel drive electric motor, powered, in the case of the V70 PHEV, by an 11.3 kWh Li-ion battery pack (8 kWh is usable) under the trunk floor. (Earlier post.)

The V70 diesel PHEV is projected to support up to a 50 km (31 mile) all-electric range—sufficient to cover the daily transport needs of 75% of European drivers. Carbon dioxide emissions will average out at 49 g/km, with fuel consumption of 1.9 liters per 100 km (124 mpg US), according to the NEDC certification driving cycle.

Green Car Congress spoke with Gustavsson on the phone following Volvo’s affirmation at the Paris Motor Show that it would introduce a series-produced plug-in hybrid diesel as early as 2012. (Earlier post.)

Volvo concept of a range-extended architecture. Click to enlarge.

Gustavsson said that in the medium- to long-term, Volvo would consider a series hybrid architecture—i.e., a purely electric drive vehicle with a small range-extending ICE.

The plug-in hybrid is a perfect bridge to an electric society. We think that [a range-extended electric vehicle] would be an alternative in the long term, if we have a bridge. Plug-in hybrids are expensive—they’re a combination of two expensive drive trains. But that’s a bridge to get used to electrification, to get away from range anxiety.

The next step would be [around] 2016, 2017, 2018. We will still have a range limitation with battery cars. But we would avoid that if we put in a small range extender, say a 1-cylinder, 15 hp (11 kW) engine, very small, or a fuel cell. We think it’s probably long term the most interesting.

But it is at such an early stage. What we do right now is try to listen. We have our hands full to deliver a plug-in hybrid and a battery car [the electric C30].

—Paul Gustavsson

Based on the NEDC cycle, CO2 emissions from Volvo’s V70 plug-in diesel hybrid will average out at 49 grams per kilometer, with fuel consumption of 1.9 liters per 100 km (124 mpg US), according to Volvo. The diesel engine—optimized to run on renewable synthetic diesel and complying with future exhaust emission requirements—can be run separately or in combination with the electric motor for optimal power and energy utilization.

Volvo plans to launch its PHEVs in all markets, including the US, and is working to develop a gasoline-engined PHEV to that end. The company is also evaluating the introduction of diesel-engined PHEVs into the US market, although the cost to meet US emissions requirements is a challenge, Gustavsson said.

Another cost-related challenge facing PHEV and EV introduction, Gustavsson said, is government support, which is “absolutely critical” in the beginning.

A lot of countries are hesitating in the budget. It is a mixed picture. In some markets, they withdraw from earlier promises; some markets increase, like Sweden. It’s a mixed picture.

—Paul Gustavsson



Interesting and flexible.. "The next step would be [around] 2016, 2017, 2018. We will still have a range limitation with battery cars. But we would avoid that if we put in a small range extender, say a 1-cylinder, 15 hp (11 kW) engine, very small, or a fuel cell."

If Volvo calculated only 15 hp will eliminate range anxiety, that can be done it many inexpensive ways.


Wise decision. PHEVs will be around for the next 15+ years or until such time as batteries energy density is 600+ Wh/Kg and their price is down close to $100/Kwh.

Range extenders don't have to be 300 hp V-6. Something around 15 to 20 Kw would be enough for a well designed mid size car.

People who are convinced that they need more could buy e-race cars.


"renewable synthetic diesel"

This is a good idea. Hub motors have limits, we will see what actually gets used over time in most cars.


Volvo V70 is rather heavy therefore I would say 20 kW range extender would be normal for highway driving. May be C30 would be enough 11 kW.


A 15 hp range extender will work for a lightweight, aerodynamic car as long as it retains enough battery capacity for hill climbing. Always keeping that much spare battery capacity is expensive, though, because you pay for a lot of battery that you almost never use. Tricks such as the Volt's "Mountain Mode" might help here.


GPS could tell my car to use mountain mode. If I am driving east on highway 80 past Auburn in California, I am going to encounter a mountain pass soon.


This architecture is much better than the Volt one, will result in much lighter and better efficiency in charger sustaining as well as better performances.

The series architecture of the Volt is a failure, too heavy, inefficient (only 35MPG in charge sustaining mode) too expensive, and allowing only poor performance in all cases.

Parallel architecture is better


I like the idea of a small genset running more often as a range extender.

The 11kW genset mentioned could generate 3 phase AC and feed it straight to the motor, any additional power would come from the battery pack. Having a range extender running more often keeps the batteries at a higher average state of charge, stops you having a problem with fuel going off in the tank.


A mass produced, standardized, ultra light weight 15 Kwh., one or two cyls genset or an equivalent capacity FC should not cost a fortune if built in countries with low labor cost.

Why not build a few multi-fuels genset factories in African seaport cities where unemployment is often over 50 %.


All gensets should be flex fuel capable of running M85, this is not difficult nor expensive to do. The alternator has to put out enough to run the car AND charge the batteries at the same time, otherwise all you have is a series hybrid.

So if it takes 20 kW to run the car at 70 mph, you might want another 20 kW to charge that batteries in maybe 20 minutes. So a 40 kW alternator and maybe a 70 hp at 3000 rpm engine should do it.


A well designed, light weight, low drag, low rolling resistance, mid-size car should not require 70 hp to keep it going indefinitely at 100 kph. With rare accelerations and hills, 15/20 Kw should do it. Braking energy capture in city traffic could supply most of the energy required for acceleration. You cannot drive up hill all the time. One must also drive down hill, even if you live on top of the mountain. Most of the energy used to go up hill could be captured coming down hill.


I said 20 kW at 70 mph, NOT 70 hp. You need to run the car with 20 kW and charge the batteries with 20 kW at the SAME time. That is a 40 kW alternator driven by a 70 hp engine at 3000 rpm. The engine runs for 20 minutes and shuts off for 20 minutes while the car runs on batteries.

Roger Pham

There is no need to charge the battery while driving at 70 mph. If you want to charge the battery while driving, try reducing the speed down to 60 mph. Also, on downhill run, the car can run at 70 mph while charging the battery. On an uphill run, how about slowing down to 55 mph for a change? Or, if you have charged the battery sufficiently on the downhill run, you can use the motor to boost the total output, so that you can climb up hill for a good distance at 70 mph.

There is a big deal of cost, size, and weight differential between a 45 kW engine coupled to a 40 kW generator, vs a 22.5 kW engine coupled to a 20 kW generator. I'd rather have a 1/2 size genset and have rooms to spare for my luggages on a cross country trip. I'd rather save a few thousands $$ off the initial purchase price of my vehicle that'll give me at least the bragging right for being smart enough to get the most bangs for the buck. I'd rather not dragging around the dead weight of excessive and useless engine and generator weight if I can help it. I like the nimble feeling of driving a lighter car without excessive dead weight, that will save energy and reduce my electric bills further.


Around here people drive 70 mph commuting 40-50 miles each way. Unless they have a charger at work an EV gets a bit used up. I think the range extended PHEVs will be a big hit. They use fewer expensive batteries and if you forget to plug it in you can still get to work in the morning.

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